AndroidOverlay implementation using Dialog.

content/browser/android/dialog_overlay_operations_impl.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/android/dialog_overlay_operations_impl.h"
+
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+#include "gpu/ipc/common/gpu_surface_tracker.h"
+#include "jni/DialogOverlayOperationsImpl_jni.h"
+#include "ui/android/window_android.h"
+
+using base::android::AttachCurrentThread;
+using base::android::JavaParamRef;
+using base::android::ScopedJavaLocalRef;
+
+namespace content {
+
+// static
+bool DialogOverlayOperationsImpl::RegisterDialogOverlayOperationsImpl(
+    JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+static jlong RegisterForTokens(JNIEnv* env,
+                               const JavaParamRef<jobject>& obj,
+                               jlong high,
+                               jlong low) {
+  return reinterpret_cast<jlong>(new DialogOverlayOperationsImpl(
+      obj, base::UnguessableToken::Deserialize(high, low)));
+}
+
+static void UnregisterForTokens(JNIEnv* env,
+                                const JavaParamRef<jobject>& obj,
+                                jlong handle) {
+  delete reinterpret_cast<DialogOverlayOperationsImpl*>(handle);
+}
+
+DialogOverlayOperationsImpl::DialogOverlayOperationsImpl(
+    const JavaParamRef<jobject>& receiver,
+    const base::UnguessableToken& token)
+    : receiver_(receiver), token_(token), cvc_(nullptr) {
+  cvc_ = GetContentViewCore();

[boliu, 2017/03/30 22:42:02]

DCHECK everything here is on UI thread

[liberato (no reviews please), 2017/04/04 17:49:28]

Done.

+
+  // If there's no CVC, then just post a null token immediately.
+  if (!cvc_) {
+    JNIEnv* env = AttachCurrentThread();
+    Java_DialogOverlayOperationsImpl_onDismissed(env, receiver_.obj());
+    // |this| might be destroyed.
+    return;
+  }
+
+  cvc_->AddObserver(this);
+
+  // Also send the initial token, since we'll only get changes.
+  if (ui::WindowAndroid* window = cvc_->GetWindowAndroid()) {
+    ScopedJavaLocalRef<jobject> token = window->GetWindowToken();
+    if (!token.is_null()) {
+      JNIEnv* env = AttachCurrentThread();
+      Java_DialogOverlayOperationsImpl_onWindowToken(env, receiver_.obj(),
+                                                     token);
+    }
+  }
+}
+
+DialogOverlayOperationsImpl::~DialogOverlayOperationsImpl() {
+  if (cvc_)
+    cvc_->RemoveObserver(this);
+}
+
+void DialogOverlayOperationsImpl::OnContentViewCoreDestroyed() {
+  cvc_ = nullptr;
+
+  JNIEnv* env = AttachCurrentThread();
+  Java_DialogOverlayOperationsImpl_onDismissed(env, receiver_.obj());
+  // |this| might be destroyed.

[boliu, 2017/03/30 22:42:02]

what if you use DeleteSoon in UnregisterForTokens to avoid re-entrancy issues
like this?

[liberato (no reviews please), 2017/04/04 17:49:28]

good point.  i'll explicitly remove the CVC observer to prevent additional token
callbacks while the delete is pending.  won't make a difference if this is in
response to onDismissed, but the java side can unregister for other reasons.

+}
+
+void DialogOverlayOperationsImpl::OnAttachedToWindow() {
+  JNIEnv* env = AttachCurrentThread();
+
+  ScopedJavaLocalRef<jobject> token;
+
+  if (ui::WindowAndroid* window = cvc_->GetWindowAndroid())
+    token = window->GetWindowToken();
+
+  Java_DialogOverlayOperationsImpl_onWindowToken(env, receiver_.obj(), token);
+}
+
+void DialogOverlayOperationsImpl::OnDetachedFromWindow() {
+  JNIEnv* env = AttachCurrentThread();
+  Java_DialogOverlayOperationsImpl_onWindowToken(env, receiver_.obj(), nullptr);
+}
+
+ContentViewCoreImpl* DialogOverlayOperationsImpl::GetContentViewCore() {
+  // Get the frame from the token.
+  content::RenderFrameHost* frame =
+      content::RenderFrameHost::FromOverlayRoutingToken(token_);
+  if (!frame) {
+    DVLOG(1) << "Cannot find frame host for token " << token_;
+    return nullptr;
+  }
+
+  content::WebContents* web_contents =
+      content::WebContents::FromRenderFrameHost(frame);
+  if (!web_contents) {

[boliu, 2017/03/30 22:42:02]

there's a chromium-dev thread by dcheng that this can't be null :p

[liberato (no reviews please), 2017/04/04 17:49:28]

DCHECK it is then!

+    DVLOG(1) << "Cannot find web_contents for token " << token_;
+    return nullptr;
+  }
+
+  content::ContentViewCoreImpl* cvc =
+      content::ContentViewCoreImpl::FromWebContents(web_contents);
+  if (!cvc) {
+    DVLOG(1) << "Cannot find cvc for token " << token_;
+    return nullptr;
+  }
+
+  return cvc;
+}
+
+static jint RegisterSurface(JNIEnv* env,
+                            const base::android::JavaParamRef<jobject>& jcaller,
+                            const JavaParamRef<jobject>& surface) {
+  return gpu::GpuSurfaceTracker::Get()->RegisterViewSurface(surface.obj());
+}
+
+static void UnregisterSurface(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& jcaller,
+    jint surface_id) {
+  gpu::GpuSurfaceTracker::Get()->UnregisterViewSurface(surface_id);
+}
+
+}  // namespace content